Non-volatile memory systems, such as flash memory, are used in digital computing systems as a means to store data and have been widely adopted for use in consumer products. Flash memory may be found in different forms, for example in the form of a portable memory card that can be carried between host devices or as a solid state disk (SSD) embedded in a host device. These memory systems typically work with data units called “pages” that can be written, and groups of pages called “blocks” that can be read and erased, by a storage manager often residing in the memory system.
A non-volatile memory system may develop problems with efficiency as it becomes more filled with data. Over time, data associated with sequential logical addresses can become scattered over different physical locations in the memory. This fragmentation of the data within a memory system can lead to delays in response time for the memory system as the memory fills up because fewer free blocks may be available for incoming data and the memory system may then need to attend to housekeeping operations to free up more space. The housekeeping operations require more effort by the memory system when the data that is made obsolete by incoming updated data is scattered over multiple different blocks.